Heavy-duty Engine Standards

November 27, 2018

Outline

• Evolution of Heavy-Duty Engine Standards and Technologies• Past and Present

• Need for Emission Reductions• Heavy-Duty Low NOx Plan• Heavy-Duty Low NOx Measures • Heavy-Duty Low NOx Demonstration Projects

•Questions

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Evolution of Heavy-Duty Engine Standards and Technologies

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Evolution of Heavy-Duty Engine Standards

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<1990 1991 1994 1998 2004 2007 2010

Emis

sion

Sta

ndar

d (g

/bhp

-hr)

Model Year

NOx PMx10

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1990-1994 Engine Optimization• NOx standard from 6.0 to 5.0 g/bhp-hr in 1991

• PM standard from 0.6 to 0.25 g/bhp-hr in 1991 and • 0.1 g/bhp-hr in 1994

• Main Technologies/Strategies• Injection timing retard• Reduced intake manifold temperature• Electronic fuel injection• Increased fuel injection pressure

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1998 Engine Optimization• NOx standard from 5.0 to 4.0 g/bhp-hr in 1998

• Main Technologies/Strategies• Wide-spread use of electronic controls• Improved combustion chamber design• Increased fuel injection pressure

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2004 Engine Optimization• NOx standard reduced from 4.0 to about 2.0 g/bhp-hr (2.4 g/bhp-hr

NOx+NMHC) in 2004

• Main Technologies• Cooled Exhaust Gas Recirculation (Cooled EGR)• Variable geometry turbocharger (VGT)• Common rail fuel injection

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2007+ Aftertreatment Devices• NOx reduced to 0.2 g/bhp-hr NOx and NMHC to 0.14 g/bhp-hr from

combined NOx+NMHC standard of 2.4 g/bhp-hr• Phased-in on a percent-of-sales basis:

• 50% in 2007-2009 and 100% in 2010

• 2007-2009 engines were certified to a fleet average NOx of about 1.2 g/bhp-hr

• PM reduced from 0.1 to 0.01 g/bhp-hr

• Main Technologies: 2007-2009• Increased cooled EGR

• Diesel Oxidation Catalysts (DOC)

• Catalyzed Diesel Particulate Filter (DPF), and

• Ultra Low Sulfur Diesel (ULSD)

• 15 ppm Sulfur 8

Current Standard:2010+ MY HD Engine Standard• NOx =0.20 g/bhp-hr and PM = 0.01 g/bhp-hr • Main technologies

• DOC • DPF • Urea-Selective Catalytic Reduction (Urea-SCR) • Ammonia Slip Catalyst (ASC) • Cooled EGR, VGT, high pressure injection, and other engine management

strategies• ULSD

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Otto-Cycle Engines• Similar emission standards as diesel engines

• Include gasoline, natural gas, and other fuels• From 1990 to 2008, >90% reduction in NOx standards; >80% reductions in HC• Current standards same as diesel engines

• Emission control technologies• Three-way catalysts• Cooled EGR• Engine improvements

• Air-fuel ratio control, air handling, and combustion improvements

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Continued Need for Emission Reductions

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Air Quality Challenges• Over 12 million Californians breathe

unhealthy air

• Most areas expected to attain standards by 2026

• Key challenges:• South Coast ozone• San Joaquin Valley PM2.5

Ozone: 0.75 ppb 8-hourStandard (2008)

PM2.5: 12.0 µ/m3 AnnualStandard (2012)

Nonattainment Areas in CaliforniaOzone and PM2.5

Marginal – Ozone

Moderate – Ozone

Moderate – PM 2.5

Serious – Ozone

Severe – Ozone

Extreme – Ozone / Serious – PM2.5

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• NOx benefits by 2031 with current program

• Mobile source emissions reduced over 50 percent

• Heavy-duty vehicle emissions reduced by nearly 70 percent

• Heavy-duty trucks and federal sources remain largest contributors

• Heavy-duty trucks emit 33 percent of statewide NOx, 509 tpd

• Need to reduce heavy-duty NOx by 90 percent

South Coast Emissions Inventory Key Sources

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0

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2015 2031

Light-DutyVehicles

Heavy-DutyVehicles

Off-RoadFederal andInternationalSources

Off-RoadEquipment

South Coast Mobile Source NOx Emissions (tons per day)

050

100150200250300350400

Today 2031

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Updated 8-hour Air Quality Standard for Ozone – 70 ppb

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Source: U.S. EPA Green Book, https://www3.epa.gov/airquality/greenbook/map8hr_2008.htmlMap shows areas designated nonattainment by EPA as of 4/30/2018

Current Ozone Nonattainment Areas, 4/30/2018 (2008 Standard, 0.075 ppm)

Updated 8-hour Air Quality Standard for Ozone(2015 Standard, 70 ppb)

Source:https://ozoneairqualitystandards.epa.gov/OAR_OAQPS/OzoneSliderApp/index.html#

‘til 2023:• Pre-2010s dominate NOx

→ Ensuring Truck and Bus compliance

2023+:• Deterioration-related emissions are

largest→ Need HD I/M and extended warranty

• Running, start and idling emissions also significant→ Need lower standards, low-load

cycle, improved in-use testing15

Breakdown of NOx Emissions from Heavy-Duty Vehicles

Source: S. Pornazieri, AQPS, CARB

Evidence for Off-Cycle Emissions

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Challenges to Meeting Low NOx Emissions • Cold start conditions

• Controlling NOx during warm up• Accelerating catalyst warm-up

• Controlling NOx at low-load operations

• Maintaining high efficiency NOx control during warm operation • High exhaust temperature• Space velocity management• Durability

• Must be accomplished with minimal fuel economy impact

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NOx Emissions from 2010+ Heavy Duty Engines

(Above 33,000 lbs. GVWR) in Year 2031

Heavy-Duty Low-NOx Plan

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CARB Optional NOx Standards• Optional NOx standards: 2015+ MY Engines

• 90%, 75%, and 50% below 2010 NOx standards• 0.02 g/bhp-hr, 0.05 g/bhp-hr, and 0.10 g/bhp-hr

• Engines certified to the optional NOx standards:• 0.02 g NOx/bhp-hr (90% below current standard)

• Cummins ISX12N - 11.9L CNG • Cummins ISL G - 8.9L CNG • Greenkraft V8 - 8.0L Gasoline, CNG, and LPG • Encore Tec 6.8L CNG

• 0.05 g NOx/bhp-hr (75% below current standard)• Encore Tec - 6.0L CNG • Roush CleanTech V10 - 6.8L LPG • Westport - 6.8L CNG

• 0.10 g NOx/bhp-hr (50% below current standard)• Roush CleanTech V10 - 6.8L CNG • Cummins ISB6.7 - 6.7L CNG

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Establishing Low-NOx HD Engine Program• Goals:

• Develop HD Low-NOx engine standard• Develop Low-Load Cycle• Improve in-use compliance test• Extended warranty and useful life• Improved durability demonstration procedures • Simultaneous path to Low-NOx and Phase 2 GHG

• Timeframe: • CARB Board date: December 2019• Implementation schedule: 2023 – 2027

• More info at:https://www.arb.ca.gov/msprog/hdlownox/hdlownox.htm

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Developing a Supplemental Low Load Certification CycleBackground• Current certification cycles (HD-FTP and RMC/SET) do not

account for sustained low load operations

• HD-FTP is not of sufficient length to verify active thermal management of SCR systems

Objective• Develop a new HD engine test cycle that:

• Represents real-world urban tractor and vocational vehicle operations that are characterized by low engine loads

• Is of sufficient length such that continuous active thermal management is required

• Has an emission standard that balances the need for NOx emission reductions and any associated GHG emission impacts

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Improving In-use Testing Program

• Current in-use compliance requirements: Not to Exceed (NTE) method

• Applies only in certain conditions• Overlooks emissions behavior during the majority of In-Use operations• Significant number of engines pass ‘by default’ without any NTE events

• Goal: Leverage tools developed under NTE to apply an In-Use Emissions Standard to breadth of vehicle operation

• Examining alternative Emissions Metrics and Windowing Methods• ~10% VMT projected to drive 50% of the NOx inventory: Need much

wider coverage in Time and in Load• Both OEM and CARB run testing

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ExaminableNTE Events

5.8%

InsideNTE Zone,

but Excluded50.1%

OutsideNTE Zone

44.1%

Fraction of Time,A Line-haul Application

Revising Useful Life Provisions• Proposed Amendments

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VEHICLE / ENGINE CATEGORY

CURRENT USEFUL LIFE

LENGTHENED USEFUL LIFE

Class 8 Heavy-HeavyGVWR > 33,000 lbs.

435,000 mi10 yrs / 22,000 hrs

~ 1-1.2 million mi15 years / hours TBD

Class 6-7 Medium-Heavy19,500 lbs. < GVWR ≤ 33,000 lbs.

185,000 mi10 yrs

~ 500,000 -550,000 mi15 years

Class 4-5 Light-Heavy14,000 lbs. < GVWR ≤ 19,500 lbs.

110,000 mi10 yrs

~ 250,000 –550,000 mi15 years

Revising Warranty Period Requirements• Proposed Amendments

* Applies to 2022+ MY vehicles

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VEHICLE / ENGINE CATEGORY

CURRENT WARRANTY

JUNE 2018WARRANTY

AMMENDMENTS*

LENGTHENED WARRANTY

Class 8 Heavy-HeavyGVWR > 33,000 lbs.

100,000 mi5 yrs / 3,000 hrs

350,000 mi5 yrs

≥435,000 mi5 years

Class 6-7 Medium-Heavy19,500 lbs. < GVWR ≤ 33,000 lbs.

100,000 mi5 yrs / 3,000 hrs

150,000 mi5 yrs

≥185,000 mi5 years

Class 4-5 Light-Heavy14,000 lbs. < GVWR ≤ 19,500 lbs.

100,000 mi5 yrs / 3,000 hrs

110,000 mi5 yrs

TBD

Low NOx Demonstration Projects

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Low NOx Demonstration Projects• Stage 1 – Low NOx Feasibility Demonstration

• Funding: $1.6M by CARB with support from MECA and Volvo• Final report at: https://www.arb.ca.gov/research/veh-emissions/low-nox/carb_2017-04-

30_03-19503_finaledit.pdf

• Stage 1b – Re-aging of Stage 1 Aftertreatment Parts• Funding: $480,000 by SCAQMD with support from MECA

• Stage 2 – Low Load Duty Cycle (LLC) Development/ Low Load NOx Control• Funding: $1.05M by CARB

• Stage 3 – Low NOx Demonstration on an Alternative Non-Turbocompound(TC) Engine• Funding: $1.375M by CARB, SCAQMD and POLA with support from Cummins & MECA

• Stage 3b – Additional Low NOx Related Engine Hardware Development• Funding: $500K by EPA, CHEDE & MECA

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Stage 1: Low NOx ProgramObjectives• Started October 2013

• Completion date: May 2017

• Optimization on regulatory cycles• Target NOx on aged parts: 0.02 g/bhp-hr on the FTP and RMC

• Includes a 12 L natural gas and 13 L diesel engine

• Solution must be technically feasible for production

• Solution must be consistent with path toward meeting future GHG standards CO2, CH4, N2O

More information: https://www.arb.ca.gov/research/veh-emissions/low-nox/low-nox.htm 27

• Diesel • Screened approximately 33 technology packages• Final low NOx configuration: PNA+MB+DEF+SCRF+SCR+ASC• Demonstrated on development parts: 0.012 g/bhp-hr NOx • Impact on GHG from baseline: 2% on FTP

• Natural Gas • Engine upgraded to improve air fuel ratio control• Aftertreatment options: 4 packages of three way catalysts (TWC)• Final down selected aftertreatment configuration:

• Close-coupled TWC (9L) and underfloor TWC (20L)

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Stage 1: Final Low NOx Configuration

• Diesel• Final parts aged on engine thermally and chemically • Unexpected PNA canning failure during aging• PNA and SCRF were cleaned, recovered, and continued aging to

the full useful life• Despite canning failure results were encouraging: • Diesel NOx : 0.034 g/bhp-hr on FTP and 0.038 g/bhp-hr on RMC

• Natural Gas • Final parts aged thermally to full useful life• CNG NOx: 0.010 g/bhp-hr on FTP and 0.001 g/bhp-hr on RMC

Overall Stage 1 results

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Diesel

Natural Gas

Low NOx Demonstration Projects – Stage 1b

• Contract info• Initiated in Feb 2018, to be completed by Jun 2018• Funding: $480,000 by SCAQMD with support from MECA• Contractor: SwRI

• Objectives• Re-age Stage 1 aftertreatment parts, due to failure experienced during the

original aging process that resulted in suspected hardware damage

• Status• Completed aging process• Currently performing final tests over FTP and RMC

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Low NOx Demonstration Projects – Stage 2• Contract info• Initiated in Jan 2017, to be completed in Dec 2018• Funding: $1.05M by CARB• Contractor: SwRI (with NREL as subcontractor)

• Objectives• Develop low load profiles and combine them into a Low Load Cycle (LLC)

that could be used for certification• Re-calibrate Stage 1 engine/AT system to achieve ultra-low NOx levels

under low load operation• Examine different “load” metrics for improvement of in-use testing

• Characterize accuracy of broadcast ECM torque and fueling rate• Develop proper metrics for evaluating low load operation

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Low NOx Demonstration Projects –Stage 2• Status

Low Load Cycle Development• Several candidate cycles developed• Baseline testing currently being performed• Final LLC to be released shortly

Low Load Recalibration• Awaiting completion of Low Load Cycle development and baseline testing • Calibration over low loads to begin shortly• Work on both engine-based and AT-based (mini-burner) approaches

Low Load Metric Testing• Three candidate Class 8 engines from three different manufacturers• Test Variables: broadcast torque, fuel rate, NOx sensor data (NOx and O2) , exhaust flow• Data analysis currently in progress 32

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Candidate Low Load Cycle

Low NOx Demonstration Projects –Stage 3• Contract info

• Initiated in Jun 2017, to be completed in Jun 2019• Funding: $1.325M by CARB and SCAQMD• Additional support from Cummins (2017 MY X15 engine) and MECA (AT parts

and final aging)• Contractor: SwRI

• Objectives• Optimization on FTP, RMC, and CARB Idle

• Target NOx emission rate: 0.02 g/bhp-hr on FTP and RMC

• Optimization on low load profiles developed from Stage 2

• Status• Baseline testing on regulatory cycles completed 33

Low NOx Demonstration Projects – Stage 3b• Contract info

• Initiated in Dec 2017• Funding: $500K by EPA, CHEDE and MECA• Contractor: SwRI

• Objectives• Explore additional engine hardware options on Stage 3 engine to help reduce GHG

impact and simplify AT system configuration• Options to be considered include: cylinder deactivation, turbine bypass, EGR cooler

bypass, charge air cooler (CAC) bypass, insulated exhaust manifold

• Status• Cylinder deactivation and EGR cooler bypass testing in progress• Insulated exhaust manifold and turbine bypass testing completed

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Questions?

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ContactsStephan Lemieux Manager, On-Road Heavy-Duty Diesel Section(626) 450-6162stephan.lemieux@arb.ca.gov

Daniel Hawelti, Staff Air Pollution Specialist(626) 450-6149 daniel.hawelti@arb.ca.gov

Lee Wang, Air Resources Engineer(626) 450-6145lee.wang@arb.ca.gov

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Further InformationCARB Website https://ww2.arb.ca.gov/

Heavy-Duty Low NOx Programhttps://www.arb.ca.gov/msprog/hdlownox/hdlownox.htm

Optional Reduced NOx Emission Standards for On-Road Heavy-duty Engineshttps://www.arb.ca.gov/msprog/onroad/optionnox/optionnox.htm

Technology and Fuels Assessmentshttps://www.arb.ca.gov/msprog/tech/tech.htm

On-Road Heavy-Duty Vehicle Programhttps://www.arb.ca.gov/msprog/onroadhd/onroadhd.htm

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Backup Slides

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0

1

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4

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<1990 1991 1994 1998 2004 2007 2010

Emis

sion

Sta

ndar

d (g

/bhp

-hr)

Model Year

NOx

PMx10

Evolution of Heavy-Duty Engine Standards and Technology

Same as 1990 plus electronic fuel injection, Increased Injection pressure, reduced intake manifold temperature

Continued improvement of previous technologies

Same as 1991-94 plus advances in combustion chamber design, electronic controls, Electronic unit injectors (1500-1700 bar)

Same as 1998 plus cooled EGR, VGT, common rail fuel inj. (1800-2000 bar)

Same as 2004 plus high EGR, DOC, DPF, ULSD

Same as 2007 plus Urea-SCR

Injection timing retard, some charge air cooling

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Example of Compliant 2010 HDDE

40Source: http://energy.gov/eere/vehicles/downloads/roadmap-and-technical-white-papers-21st-century-truck-partnership

Heavy-Duty Engine Certification• Engine (versus vehicle) certification due to many

engine/transmission/chassis combinations

• Engine dynamometer testing • g/bhp-hr (versus g/mi for vehicles)• Transient FTP and SET Tests• Not-to Exceed Test (NTE)

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